Five groups of investigators from six different institutions will carry out an in-depth study of many aspects of the problem of vitiligo. People with vitiligo develop white patches on the skin and while most of these individuals are in good general health, a high percentage have disorders of autoimmunity. Many patients with melanomas develop vitiligo. The incidence of vitiligo in the general population is approximately one percent. Because much about vitiligo is not well understood, and because treatment is inadequate, most physicians have not been interested in this disease, and they offer little in the way of emotional support for people with vitiligo. However reliable data show that in the United States and in other parts of the world, vitiligo is a major disorder and that it is devastating to most of the people who have it. The darker the normal skin of an individual, the more severe are the psychosocial problems when that person develops vitiligo. Destructive lesions in the pigmentary layers of the retina may occur. Vitiligo is closely related to disorders of autoimmunity and bears important relationships to melanomas. To explore the causes, effects and treatment of vitiligo and to use the information to treat patients with melanomas, we propose to carry out the following projects: 1) A detailed study of the clinical characteristics of vitiligo; the differentiation of vitiligo from other disorders of hypopigmentation; and the role of the immune system in the etiology of vitiligo. 2) A study on the effect of vitiligo on pigment cells of the eyes and ears. 3) A study on the psychosocial aspects of vitiligo. 4) The development of a rational way to use psoralens for repigmentation and/or new compounds for depigmenting patients with extensive vitiligo. 5) Development of model systems, using the DAM chickens and mice, for controlled experiments to determine the causes of vitiligo. 6) To test new treatments for patients with primary melanomas as well as those with metastatic disease.